Systems and methods for lead frame locking design features are provided. In one embodiment, a method comprises: fabricating a lead frame for a chip package, the lead frame having a paddle comprising a step-out bottom locking feature profile across at least a first segment of an edge of the paddle that provides an interface with a mold compound; etching the paddle to have at least a second segment of the edge having either an extended-step-out bottom locking feature profile or an overhanging top locking feature profile; and alternating first and second segments along the edge of the paddle.
Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A method comprising: fabricating a lead frame for a chip package, the lead frame having a paddle that includes a step-out bottom locking feature profile across at least a first segment of an edge of the paddle that provides an interface with a mold compound; fabricating the paddle to include at least a second segment of the edge with an extended-step-out bottom locking feature profile, wherein a step-out of the second segment has a greater width than a step-out of the first segment; and alternating first and second segments along the edge of the paddle.
A method for manufacturing chip packages involves creating a lead frame with a paddle. A first section of the paddle's edge has a "step-out bottom locking feature," which provides a wider surface for better adhesion to the mold compound used later. A second section of the paddle's edge has an "extended-step-out bottom locking feature," meaning the step-out is even wider than the first section. These first and second sections alternate along the paddle's edge to improve the mechanical bond between the lead frame and the mold compound.
2. The method of claim 1 , further comprising: securing at least one die to the paddle.
The method for manufacturing chip packages, as described previously where a lead frame is created with alternating step-out bottom locking feature profiles along its edge, also includes attaching at least one semiconductor die to the lead frame's paddle before encapsulation.
3. The method of claim 2 , further comprising: encapsulating the paddle and the at least one die in a molding compound that secures the first segment and the second segment to the molding compound.
The chip package manufacturing method, which involves a lead frame paddle with alternating "step-out" and "extended step-out" bottom locking features, and securing a die to the paddle, further includes encapsulating the paddle and die in a molding compound. This compound fills the step-out features, mechanically locking the lead frame to the molded plastic and securing the die within the package.
4. The method of claim 3 , further comprising: fabricating one or more secondary elements of the paddle to have an overhanging-top locking feature profile, wherein the one or more secondary elements are secured to the molding compound by the overhanging-top locking feature profile.
The chip package manufacturing method, already described as using alternating step-out locking features on the paddle edge and encapsulation with molding compound, further incorporates "overhanging-top locking features" on secondary elements of the paddle. These overhanging features grip the molding compound from above, providing an additional layer of mechanical interlocking and improving the overall package robustness.
5. The method of claim 1 , further comprising etching the lead frame to fabricate the step-out bottom locking feature for the first segment and the extended-step-out bottom locking feature profile for the second segment.
The chip package manufacturing method, which uses alternating step-out bottom locking feature profiles on a lead frame paddle, creates these features by etching the lead frame. Etching is used to form both the standard "step-out bottom locking feature" in the first segment and the "extended-step-out bottom locking feature" in the second segment.
6. The method of claim 1 , further comprising stamping the lead frame to fabricate the step-out bottom locking feature for the first segment and the extended-step-out bottom locking feature profile for the second segment.
The chip package manufacturing method, which uses alternating step-out bottom locking feature profiles on a lead frame paddle, creates these features by stamping the lead frame. Stamping is used to form both the standard "step-out bottom locking feature" in the first segment and the "extended-step-out bottom locking feature" in the second segment.
7. A method comprising: fabricating a lead frame for a chip package, the lead frame having a paddle comprising a step-out bottom locking feature profile across at least a first segment of an edge of the paddle that provides an interface with a mold compound; fabricating the paddle to have at least one second segment of the edge having a overhanging top locking feature profile; and alternating first and second segments along the edge of the paddle.
A method for manufacturing chip packages involves creating a lead frame with a paddle. A first segment of the paddle's edge has a "step-out bottom locking feature," providing a wider surface for adhesion to the mold compound. A second segment has an "overhanging top locking feature" that creates a mechanical interlock with the mold compound from above. These first and second segments alternate along the paddle's edge to enhance bonding between the lead frame and mold compound.
8. The method of claim 7 , further comprising: fabricating the paddle to provide a third segment between each first segment and second segment, the third segment providing a clearance gap.
The method for manufacturing chip packages described previously, with alternating "step-out bottom locking feature" and "overhanging top locking feature" segments, also includes a third segment positioned between each first and second segment. This third segment provides a clearance gap, presumably to allow for better mold compound flow or stress relief during manufacturing.
9. The method of claim 7 , further comprising: securing at least one die to the paddle.
The method for manufacturing chip packages, as described previously where a lead frame is created with alternating step-out and overhanging locking feature profiles along its edge, also includes attaching at least one semiconductor die to the lead frame's paddle before encapsulation.
10. The method of claim 9 , further comprising: encapsulating the paddle and the at least one die in a molding compound that secures the first segment and the second segment to the molding compound.
The chip package manufacturing method, which involves a lead frame paddle with alternating "step-out" bottom and "overhanging top" locking features, and securing a die to the paddle, further includes encapsulating the paddle and die in a molding compound. This compound fills the locking features, mechanically locking the lead frame to the molded plastic and securing the die within the package.
11. The method of claim 10 , further comprising: fabricating one or more secondary elements of the paddle to have an overhanging-top locking feature profile, wherein the one or more secondary elements are secured to the molding compound by the overhanging-top locking feature profile.
The chip package manufacturing method, already described as using alternating step-out and overhanging locking features on the paddle edge and encapsulation with molding compound, further incorporates "overhanging-top locking features" on secondary elements of the paddle. These overhanging features grip the molding compound from above, providing an additional layer of mechanical interlocking and improving the overall package robustness.
12. The method of claim 7 , further comprising etching the lead frame to fabricate the step-out bottom locking feature for the first segment and the extended-step-out bottom locking feature profile for the second segment.
The chip package manufacturing method, which uses alternating step-out bottom and overhanging top locking feature profiles on a lead frame paddle, creates these features by etching the lead frame. Etching is used to form both the "step-out bottom locking feature" in the first segment and the "overhanging top locking feature" in the second segment.
13. The method of claim 7 , further comprising stamping the lead frame to fabricate the step-out bottom locking feature for the first segment and the extended-step-out bottom locking feature profile for the second segment.
The chip package manufacturing method, which uses alternating step-out bottom and overhanging top locking feature profiles on a lead frame paddle, creates these features by stamping the lead frame. Stamping is used to form both the "step-out bottom locking feature" in the first segment and the "overhanging top locking feature" in the second segment.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
April 13, 2012
July 30, 2013
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.